UT Professor Learns How to Turn French Fries Into Fuel

Published: October 07, 2011

John Struss is excited about used cooking oil, though he’s not a deep-fried foodie.

The assistant professor of chemistry is excited about turning oil into usable fuel, a process he learned about during his spring sabbatical that is relatively simple to recreate. The professor toured universities in the southeast asking questions of schools with biodiesel programs. Appalachian State and Vanderbilt “blew my hat off,” he said.

Any diesel engine vehicle can run on biodiesel fuel with only minor modifications needed, making it a cheaper and greener alternative to traditional fuel. He’ll divulge more in an Oct. 10 honors symposium at 4 p.m. in the library’s AV #2 room.

“The genesis of this is kind of weird,” he said. Struss describes watching Mike Rowe’s Dirty Jobs on the Discovery Channel. Rowe was profiling a guy who collected spent deep fryer oil and turned it into biodiesel.

“The light bulb went off right then and there,” said Struss, who envisioned taking UT food services’ used cooking oil and employing it to run campus vehicles like the biology department’s research vessel, lawn equipment and catering trucks. Biodiesel is biodegradable, nontoxic and a clean burning alternative fuel and averages about $1.10 per gallon to produce.

Using a contraption no bigger than would fit in a small closet, Struss explained that in about two hours, 40 gallons of fuel can be made. The large molecules (called triglycerides) are treated with lye and methanol that convert the oil into smaller molecules, “which are your fuel and glycerin.”

The two settle like a vinegar and oil salad dressing. The lye and remaining water is filtered out through a simple refining process.

“You can have students involved from collecting the oil to adding the chemicals to it, to testing it to even pumping it into our trucks,” said Struss. He’s received a UT grant to purchase the equipment and is researching the possibility of setting up a lab on campus. “You could do independent studies with students in economics, sociology and engineering. It’s got so much potential.”

The coolest thing about biodiesel in a campus setting, said Struss, is that it takes chemistry out of the lab.

“There is a disconnect in chemistry where we do reactions in the classroom which students feel just proves the textbook right, and don’t see the real-world uses,” said Struss. “Biodiesel production is a real application of chemistry.”